Considerable efforts by armament manufacturers throughout the world have been devoted to developing automated apparatus for handling ammunition for field artillery pieces. This is particularly so in the case of mobile artillery pieces carried by armored vehicles, such as tanks. Presently the tasks of withdrawing rounds from magazine storage and loading them into the breech of a tank cannon are almost universally performed manually. A gun loader is thus an essential member of military tank crew. To accommodate his movement in retrieving shells from a magazine and ramming them into the cannon breech, considerable space must be allotted for these activities within the tank, more typically within the revolving gun turret of the tank. Adequate headroom should be provided so the gun loader can work standing up. Unfortunately, this increases the vertical profile of the tank and thus its target size. The turret must therefore be heavily armored to maximize tank and crew survivability against enemy fire. Of course, heavy armor plating adds tremendously to the weight of a tank, which then calls for a larger engine and drive train.
The factors of high profile and the consequences thereof, the elimination of a gun loader and the consequent space savings, and the prospect of higher firing rates have been the primary motivations in developing a satisfactory autoloader for tank cannons.
Of the numerous autoloaders seen in the prior art, most are highly complex, extraordinarily space-consuming, difficult to maintain and susceptible to frequent malfunction. Many of the existing designs require that the cannon return to a predetermined position, particularly in elevation, before automated loading can be effected. Thus, the cannon must be repeatedly removed from the target for reloading and returned for firing, a significant detriment to firing rate.